As a novel non-volatile memory technology, the resistive random access memory has attracted a great deal of attention due to its high density, low cost and capability of breaking through the limitations of the technology. The materials used are phase change materials, metal oxide materials, organic materials and the like. A metal bridge type resistive random access memory dominated by Cu ions or Ag ions is one of the main types of resistive devices, and its structure is usually composed of active metal electrodes such as Cu or Ag, solid electrolyte materials (such as chalcogenide materials, metals oxides and the like), and inert electrodes (such as Pt, Pd, Ru, TaN and the like). Cu is widely used as an interconnecting wire material in an advanced semiconductor preparation process, and thus the Cu-based resistive random access memory may be integrated in a back end preparation process of a standard CMOS process easily.
The mechanism of the metal bridge type resistive random access memory may be described by the redox reaction of Cu or Ag ions. Taking a Cu-based resistive device as an example, during programming, Cu atoms are ionized by an electric field and then are injected into a solid electrolyte material to be reduced to Cu atoms through the combination with electrons, and when the metal electrodes on both ends are connected by a Cu metal filament, the resistance state of the device changes from a high resistance state into a low resistance state; and an erasing process is just opposite to the programming process, a metal conducting channel breaks under the action of an external electric field, and the resistance of the device changes from the low resistance state into the high resistance state.
Taking the interface between the Cu electrode and the solid electrolyte material as a reference, Cu ions are injected into the solid electrolyte material during programming, and the Cu ions are extracted during erasing. An important aspect of the reliability of the memory is the fatigue property, that is, the circular programming and erasing times of the device. Studies find that the fatigue property failure behavior of the Cu-based resistive random access memory is mainly low resistance state failure, which is caused by the accumulation of the Cu ions in the solid electrolyte material after multiple times of programming and erasing. How to reduce the injection efficiency of injecting the Cu ions into the solid electrolyte material to improve the cumulative effect of the Cu ions in the solid electrolyte material after multiple times of erasing becomes a technical problem that needs to be solved urgently to improve the fatigue property of the device.